Clinicopathologic features and treatment response of early acute antibody-mediated rejection in Thai Kidney Transplant recipients: A single-center experience

Background Acute antibody-mediated rejection (AMR) is a major cause of early kidney allograft dysfunction. This study was conducted to examine the clinicopathologic features and long-term outcomes of early AMR in our center. Methods We retrospectively reviewed all patients who underwent kidney transplantation between January 2005 and December 2012. Patients who had histopathologic features of AMR within 3 months after transplantation were enrolled. Results Of 444 patients, early acute AMR was diagnosed in 25 patients (5.36%). Seventeen patients (68%) were highly sensitized. Histological analysis revealed acute vascular rejection and thrombotic microangiopathy in 21 (84%) and 6 (24%) patients, respectively. Staining of C4d in peritubular capillaries was detected in 6/20 patients (12%). All patients received plasma exchange (PE) 1.5 blood volume for 1-5 sessions followed by intravenous immunoglobulin (IVIG) 2 g/kg. Sixteen patients (64%) received 1-2 doses of rituximab 375 mg/m ². We repeated treatment with PE and IVIG in refractory cases. Allografts could be rescued in 20 patients (80%) whereas 5 patients (20%) lost their grafts. Kaplan-Meier survival analysis revealed lower cumulative graft survival in the early AMR group compared with patients without early AMR (1 year survival rate of 80% vs 96% and 3 survival of 64% vs 80%; P <.001). After median follow-up time of 25 months, 7/20 patients (33%) developed late AMR. Conclusion ABMR is a serious early complication after KT. Early detection and intensive treatment is mandatory for salvaging the graft. After surpassing from early AMR, long-term close monitoring is also necessary.